Inverter Question

[JustGreg]

Have a pretty simple inverter question. Say you have the same 4 devices connected to a power strip. The power strip is connected to an inverter of X size.

Would a 2000 watt and 3000 watt inverter draw the same amount of current from the batteries? I would imagine the draw would be the same because the load is the same, but does the 3000 watt unit draw more power because it is a larger unit? Remember, the exact same devices are connected to either inverter.

Saving up to get an inverter/charger installed properly, but I need a temporary fix that can be used for a couple months. Wanting to get a larger inverter to use in some other application down the road, but not at the expense of unnecessary extra battery drain.

Current battery setup is 2 x group 24 RV Deep Cycle batteries (24DC-550) from Les Schwab. Plan on swapping them out for a couple lithium ion batteries when I get the inverter/charger installed. Have a "Solar On The Side" connection ready for a briefcase solar panel for charging in between generator runs.

Thank you - Greg

[dsol]

Good question, and I am just guessing but I would think the draw would be based on the load, however, there might be fans or other ancillary things that consume more power on the larger inverter.

I would opt for the larger since you cannot upgrade later.

[dsol]

Also, while the lithium batteries are lighter and maintain a charge better they are still significantly more expensive than any less acid type of battery. In addition, the converter that charges them requires different voltage output and monitoring than most OEM converters so you will likely need to replace that too.

I went with two sealed AGM batteries for my rig and have been happy. They are less susceptible to vibration issues and can mount in any position. And I believe they hold a charge better than standard batteries, albeit nothing like a lithium. But they are just as heavy and similar capacity to traditional batteries.

So if you plan on doing lots of off grid camping and don’t want to run a generator much then lithiums are a clear winner, but if you aren’t off the grid all that much or have freedom to run a generator more frequently then you might want to take a hard look at the investment needed to switch.

From your post it seems like you have given some good thought to your plan but figured I would point out the obvious anyway.

Good luck.

[ewarnerusa]

Subscribed because I'm interested in hearing some input. I have heard advice to run a smaller inverter if loads are smaller because it is more efficient than a large inverter supplying the same loads. Maybe due to the base standby/idle draw being higher for a larger inverter? I don't know. I have both a 300 watt and a 1500 watt inverter I can use and I used to use the 300 unless I knew I would need more power. But now out of convenience I just run the big one.

[persistent]

"... same 4 devices connected to a power strip. The power strip is connected to an inverter of X size.

Would a 2000 watt and 3000 watt inverter draw the same amount of current from the batteries? I would imagine the draw would be the same because the load is the same, but does the 3000 watt unit draw more power because it is a larger unit? Remember, the exact same devices are connected to either inverter."

All inverters use some power to operate the device itself. In general a higher capacity inverter consumes more power than a small one. However, some are more efficient than others.

2000 watts requires about a 400 amp hour lead acid battery bank to support the full 2000 watts.

3000 watts requires about a 600 amp hour lead acid battery bank.

"Saving up to get an inverter/charger installed properly, but I need a temporary fix that can be used for a couple months. Wanting to get a larger inverter to use in some other application down the road, but not at the expense of unnecessary extra battery drain."

See manufacturer's specs for efficiency and power needed to operate the device.

"Current battery setup is 2 x group 24 RV Deep Cycle batteries (24DC-550) from Les Schwab. Plan on swapping them out for a couple lithium ion batteries when I get the inverter/charger installed. Have a "Solar On The Side" connection ready for a briefcase solar panel for charging in between generator runs."

2 x group 24 lead acid may support a 700 watt inverter.

[JustGreg]

Originally Posted by dsol

Good question, and I am just guessing but I would think the draw would be based on the load, however, there might be fans or other ancillary things that consume more power on the larger inverter.

I would opt for the larger since you cannot upgrade later.

I was pretty much thinking the same thing. With the exception of a smaller draw from an extra fan or LED, I would imagine it would be roughly the same. I do admit, I am not an electrical engineer.

[JustGreg]

Originally Posted by dsol

Also, while the lithium batteries are lighter and maintain a charge better they are still significantly more expensive than any less acid type of battery. In addition, the converter that charges them requires different voltage output and monitoring than most OEM converters so you will likely need to replace that too.

I went with two sealed AGM batteries for my rig and have been happy. They are less susceptible to vibration issues and can mount in any position. And I believe they hold a charge better than standard batteries, albeit nothing like a lithium. But they are just as heavy and similar capacity to traditional batteries.

So if you plan on doing lots of off grid camping and don’t want to run a generator much then lithiums are a clear winner, but if you aren’t off the grid all that much or have freedom to run a generator more frequently then you might want to take a hard look at the investment needed to switch.

From your post it seems like you have given some good thought to your plan but figured I would point out the obvious anyway.

Good luck.

Great advise dsol. I have been reading up on both battery types and was leaning towards the lithium purely for the extra run time. My wife supports some special projects at work that often have her working 10 PM to 6 AM, or even starting at 5 AM. Need to be able to power a couple laptops, extra monitors, and a hotspot without generator due to campground quiet hours. It would also be nice to be able to work without the hum of a generator if possible.

I did not realize the problems lithium has with vibration or mounting issues. The area in front of the 5th wheel has sufficient room to mount side by size, so the mounting issue is not a problem, but not sure about vibrations. Originally I was going down the dual AGM path because of cost, and swung over to lithium because of a talk with a guy at the local RV shop. He did not mention all the other things that would need to be swapped out to support this type of setup.

Much appreciated advise. I still have a ton to learn and there are 100 different ways to skin this cat.

[dsol]

To clarify I am not sure that Lithiums have any vibration issues and actually I suspect their chemistry makes them not a concern for vibration or mounting. I thought I was referring to standard lead acid batteries regarding mounting. Sorry if I was confusing in my response.

As far as your wife’s off hours power needs if the monitors are LED and the computer is a laptop I would imagine energy draw is pretty minimal and two quality AGM’s should have no trouble getting you through the night.

@Persistent seems to have a much better understanding of batteries and capacities and amp hours than I do but it sounds like you will need several batteries to run an inverter system with significant capacity.

I would think 2-3 generator hours during non quiet hours could potentially have your batteries topped off and good to go through the night, unless it is cold enough that you are running your heater because in my experience the fan that blows the air through the ducts is by far the biggest overnight draw you will have. Obviously, you won’t be running air conditioning over night unless you are in shore power ( or have a massive battery and inverter set up).

Not sure about your fridge but running on propane also draws very little power although you will be using propane of course and that is probably not sustainable long term without refilling your tanks.

And if you have LED light in your trailer or can convert to them you will also significantly cut back on power needs.

There was a period of time I was thinking how great it would be to convert over to a massive battery and inverter system but it was going to costs thousands and I just don’t boon-dock for more than a few days at a time and with my huge gas tank and big on board generator I realized it was not a good investment because I can run my generator as much as I need during the day and have ample battery capacity. So I left everything as is and found plenty of other things to spend money on!

Good luck. I will be curious to see what you decide to do and what it costs, and of course how it works for you.

[leisuresolar@gmail.com]

I've installed over 700 Battle Born Lithium batteries. They do not have a vibration reliability problem because they are properly engineered. Some cheap Chinese Lithium batteries may have a vibration issue, because they are what they are.

I personally will never use a lead acid battery again in any of my RVs. I lived in my 5er for 5 years, off-grid, and my Battle Born batteries are 7 years old. I pulled them below 50% at least 500-1000 times, and they show no signs of aging at all.

[dsol]

Originally Posted by leisuresolar@gmail.com

I've installed over 700 Battle Born Lithium batteries. They do not have a vibration reliability problem because they are properly engineered. Some cheap Chinese Lithium batteries may have a vibration issue, because they are what they are.

I personally will never use a lead acid battery again in any of my RVs. I lived in my 5er for 5 years, off-grid, and my Battle Born batteries are 7 years old. I pulled them below 50% at least 500-1000 times, and they show no signs of aging at all.

What was the total all in cost to convert and how many batteries/system size?

Thanks.

[Thawk5796]

Inverter Question:
I have a 2020 Voltage and wonder about running the TV and electric outlets without turning on the generator. Would I need an inverter for this? if so how do I find the proper one for my 2020 Voltage?

[persistent]

Originally Posted by Thawk5796

Inverter Question:
I have a 2020 Voltage and wonder about running the TV and electric outlets without turning on the generator. Would I need an inverter for this? if so how do I find the proper one for my 2020 Voltage?

There are endless options and configurations.

Generally owner's settle for powering less than everything in their trailers because a large battery bank and expensive high capacity inverter is required.

Minimal setup:
700 watt inverter will power your TV and charge cell phones.
200 amp hour battery bank.
Connect inverter directly to battery using 4 gauge cable.
Plug appliance into inverter outlet.
Use a 120 volt extension cord if necessary.

Typical Setup:
2000 watt inverter will power what could be plugged into one home outlet.
400 amp hour battery bank.
Connect inverter directly to battery bank. Use 1/0 gauge cable.
1) Plug appliances into inverter outlet. Use a 120 volt extension cord if necessary.
2) Disconnect a string of outlets from main circuit breaker panel.
Connect string of outlets to output of inverter.
3) Same as 2 above except add a transfer switch to output of inverter.
Connect string of outlets to output of transfer switch.
Connect second input of transfer switch back to main circuit breaker panel. Use the same breaker that the string of outlets was disconnected from. Use 12 gauge 120 volt sheathed cable.

Deluxe Setup:
3500 watt inverter with built in transfer switch. It will power everything in a 30 amp trailer except the air conditioner. Air conditioner will deplete battery bank fast.
800 amp hour battery bank
Install sub panel for output of inverter
lots of details to install

[Thawk5796]

This is great information. Thank you for taking the time to respond. Any idea of how much this should cost estimate?

[dsol]

Originally Posted by Thawk5796

Inverter Question:
I have a 2020 Voltage and wonder about running the TV and electric outlets without turning on the generator. Would I need an inverter for this? if so how do I find the proper one for my 2020 Voltage?

Not your exact question but I plug a small inverter into the 12 volt outlet in the cabinet under the TV and then plug the TV into that. That allows me to watch TV using the batteries with very little draw. Your TV is an LED tv from the factory and draws very little power so you can likely just do like I do.

There are probably very few things that you really need to plug into the electrical outlets that you can’t use battery packs for like charging a phone or using a laptop. All your lights and your fridge will work on house batteries. Obviously, a hair dryer or space heater are another story.

If you want to power all the outlets then Persistent gave you plenty of information, but in my opinion unless you camp a ton or are full timing, it is really expensive to allow for total battery longevity while off grid. I find when in the desert that 2-3 hours a day is more than enough to top off batteries. And if it is really hot then running air conditioning requires generator use anyway so your batteries will be full. At a campground quiet hours tend to be overnight when it is cooler anyway so generators are not necessary.

[Thawk5796]

Good information. Thank you. Yes it is just for a few hours. I appreciate your time to send me a note. Greatly appreciated.